Molecular Formula

Q.

What is ${\text{Na}}_2{\text{CO}}_3$ made up of?

1. 1 molecule of Sodium Carbonate

2. 2 atoms of sodium

3. 1 atom of Carbon

4. 3 atoms of Oxygen

Q.

Which of the following exists as molecules?

(i) Oxygen gas

(ii) Argon

(iii) Ammonia

(iv) Helium

(v) Water

(vi) Sugar

1. i, iv, ii
2. ii, iv, v
3. iii, v, vi
4. i, iii, v, vi

Q.

What will be the number of moles of oxygen in one litre of air containing 21% oxygen by volume under standard conditions?

1. 0.003

2. 0.006

3. 0.009

4. 0.012

Q.

Statement-1: $N_2$ and $H_{2}O$ are both molecules.
Statement-2: A molecule can have only similar kind of atoms.

1. Both the statements are true, and 2 explains 1

2. Only Statement-1 is true

3. Both the statements are true, and 2 doesn't explain 1

4. Only Statement-2 is true

Q.

How many moles of hydrogen atoms are present in 1 mole of ${\text{H}}_2\text{O}$?

1. 3

2. 2

3. 1

4. 4

Q. The chemical formula of ammonium nitrate is _________.

1. $N{H}_{4}N{O}_3$
2. $N{H}_4(N{O}_3{)}_2$
3. $(N{H}_4{)}_{2}N{O}_3$
4. $N{O}_{3}N{H}_4$

Q. A compound is formed when elements X and Y chemically combine with each other. X has a valency of 6 and Y has a valency of 4. The molecular formula of the compound will be _______.

1. $X_2{Y}_4$
2. $X_4{Y}_2$
3. $X_{2}Y$
4. $X{Y}_2$

Q. Who proposed the law of constant proportions?

1. John Dalton
2. Ernest Rutherford
3. Joseph Proust
4. Antoine Lavoisier

Q. In a chemical reaction, the total mass of the reactants is 50 g. What will be the total mass of the products formed?

1. 100 g
2. 50 g
3. 25 g
4. 40 g

Q. Which among the following is the chemical formula of sodium chloride?

1. NaCL
2. NaCl
3. Nacl
4. naCl